Fetch help content from repo, add TOC and marketplace troubleshooting

Help dialog now fetches HOW-TO-USE.md live from the gitea repo on open,
falling back to the compile-time embedded copy when offline. Content is
cached for the session. Removes the ~600-line hardcoded markdown constant
from HelpDialog.tsx in favor of a single source of truth.

Adds a Table of Contents with anchor links for quick navigation and a new
troubleshooting entry for the "Failed to install Anthropic marketplace"
error with the jq fix. Markdown renderer updated to support anchor links
and header id attributes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src-tauri/src/commands/help_commands.rs

@@ -0,0 +1,60 @@
+use std::sync::OnceLock;
+use tokio::sync::Mutex;
+
+const HELP_URL: &str =
+    "https://repo.anhonesthost.net/cybercovellc/triple-c/raw/branch/main/HOW-TO-USE.md";
+
+const EMBEDDED_HELP: &str = include_str!("../../../../HOW-TO-USE.md");
+
+/// Cached help content fetched from the remote repo (or `None` if not yet fetched).
+static CACHED_HELP: OnceLock<Mutex<Option<String>>> = OnceLock::new();
+
+/// Return the help markdown content.
+///
+/// On the first call, tries to fetch the latest version from the gitea repo.
+/// If that fails (network error, timeout, etc.), falls back to the version
+/// embedded at compile time. The result is cached for the rest of the session.
+#[tauri::command]
+pub async fn get_help_content() -> Result<String, String> {
+    let mutex = CACHED_HELP.get_or_init(|| Mutex::new(None));
+    let mut guard = mutex.lock().await;
+
+    if let Some(ref cached) = *guard {
+        return Ok(cached.clone());
+    }
+
+    let content = match fetch_remote_help().await {
+        Ok(md) => {
+            log::info!("Loaded help content from remote repo");
+            md
+        }
+        Err(e) => {
+            log::info!("Using embedded help content (remote fetch failed: {})", e);
+            EMBEDDED_HELP.to_string()
+        }
+    };
+
+    *guard = Some(content.clone());
+    Ok(content)
+}
+
+async fn fetch_remote_help() -> Result<String, String> {
+    let client = reqwest::Client::builder()
+        .timeout(std::time::Duration::from_secs(10))
+        .build()
+        .map_err(|e| format!("Failed to create HTTP client: {}", e))?;
+
+    let resp = client
+        .get(HELP_URL)
+        .send()
+        .await
+        .map_err(|e| format!("Failed to fetch help content: {}", e))?;
+
+    if !resp.status().is_success() {
+        return Err(format!("Remote returned status {}", resp.status()));
+    }
+
+    resp.text()
+        .await
+        .map_err(|e| format!("Failed to read response body: {}", e))
+}

app/src-tauri/src/commands/mod.rs

@@ -1,6 +1,7 @@
 pub mod aws_commands;
 pub mod docker_commands;
 pub mod file_commands;
+pub mod help_commands;
 pub mod mcp_commands;
 pub mod project_commands;
 pub mod settings_commands;

app/src-tauri/src/lib.rs

@@ -120,6 +120,8 @@ pub fn run() {
             commands::update_commands::get_app_version,
             commands::update_commands::check_for_updates,
             commands::update_commands::check_image_update,
+            // Help
+            commands::help_commands::get_help_content,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");